A bomb hidden in an ambulance killed at least 95 people and wounded about 158 in the Afghan capital Kabul when it blew up at a police checkpoint yesterday.

The Taliban claimed responsibility for the suicide blast, which happened just a week after it attacked the Intercontinental Hotel, killing more than 20 people.

Sources blamed the Haqqani network, a militant group affiliated with the Taliban which is believed to be behind many of the biggest attacks on urban targets in Afghanistan.

Hours after the blast, a spokesman said the death toll had risen to at least 95.

Medical teams struggled to handle the casualties pouring in, and some of the wounded were laid out in the open, with intravenous drips set up next to them in hospital gardens.

Mirwais Yasini, a member of parliament who was nearby when the explosion happened, said an ambulance approached the checkpoint and blew up. The target was apparently an interior ministry building nearby.

Buildings hundreds of metres away were shaken by the force of the blast, which left torn bodies strewn on the street amid piles of rubble, debris and wrecked cars.

"It's a massacre," said an aid worker at a trauma hospital that treated casualties.

The latest attack will add pressure on President Ashraf Ghani and his US allies, who have expressed confidence that a new more aggressive military strategy has succeeded in driving insurgents back from major provincial centres.